The objective of this article is to determine the prevalence and type of potential drug interactions in primary care patients.

It is very interesting because its content is directly related to medical errors and their consequences, adverse effects and drug interactions in primary care. This field has a huge impact on the global patient safety due to the high number of visits, the level of prescription and other factors such as pluripathology.

The authors start from the difficulty of identifying and confirming the actual prevalence of drug interactions, to propose a preventive approach. It is acting on potential drug interactions identified by the electronic medical records (and confirmed by prescription -recipes used-), according to the evidence available, and using software that identifies patients likely to suffer these potential interactions. All this would be completed by a warning system, related to the medical record, that, in real time, allows the family physician identify the potential interaction, and with the automatic proposal of safe therapeutic alternatives. Every active ingredient that each patient can be taking simultaneously is analyzed.

The study confirms the existence of a serious safety problem for patients, because 1 in 20 Spanish citizens is subject to the risk of drug interaction. And, more important, with a high rate of serious or high risk interactions.

At the time of analysis 29.4% of the population took medication. Of these patients, 73.9% took more than one drug and, therefore, was at risk of interactions; more than a half of the potential interactions could be clinically important. However, the percentage of interactions observed is usual in the literature.

There are more interactions among people with chronic conditions, the elderly, females and polymedicated patients. The active ingredients most frequently involved were hydrochlorothiazide, ibuprofen and acenocumarol. Respect to interactions that should be avoided, the most common are combinations with omeprazole, acenocumarol and diazepam.

This approach and the results of this study provide us valuable information and, most of all, a new simple and practical approach, which should not be wasted by the professionals or the institutions involved, for the benefit of our patients.